ZnWO₄ nanocrystals/reduced graphene oxide hybrids: Synthesis and their application for Li ion batteries

ZnWO₄, as an environment-friendly and economic material, has the potential for Li ion batteries (LIB) application. In this paper, a facile method has been developed to synthesize ZnWO₄ supported on the reduced graphene oxide (RGO) to improve its LIB performance. The cuboid-like ZnWO₄ nanocrystals are prepared by directly adding Na ₂WO₄ powders into the graphene oxide/Zn aqueous solution followed by a hydrothermal treatment. The high-resolution TEM, XRD and XPS characterizations were employed to demonstrate structural information of the as-prepared ZnWO₄/RGO hybrids carefully. Besides, we also discussed the LIB properties of the hybrids based on the detailed galvanostatic charge-discharge cycling tests. As a result, the specific capacity of the as-prepared ZnWO₄/RGO hybrids reached more than 477.3 mA h g ^-1 after 40 cycles at a current density of 100 mA g^-1 (only less than 159 mA g^-1 for bare ZnWO₄). During the whole cyclic process, the coulombic efficiency steadily kept the values higher than 90%.